Monroe County Commissioner David Rice wanted proof Wednesday that pumping equipment for a roughly $180 million central sewer system will not break down, as alleged by at least one critic of the Cudjoe Regional Wastewater System project.

Cudjoe Key resident Walter Drabinski, an electrical engineer, has reviewed project plans and questioned some of the technology and equipment that will be used in the system.

Drabinski has voiced his concerns to Florida Keys Aqueduct Authority (FKAA) and county officials, calling on them to modify their designs and technology.

Among the criticism is the use of grinder pumps. The pumps and holding tanks will be stationed in neighborhoods, and the pumps chew up the sewage before sending it along to be processed at a central treatment station. They are similar to, but much stronger than a sink's garbage disposal.

Drabinski is concerned the pumps will become clogged by anything from household goods like children's toys to organic materials like sand and rocks.

Commissioner Rice called upon the manufacturers of the grinder pumps to give a demonstration Wednesday of what things the pumps can handle and chew up with its metal teeth and blades. They stuffed latex gloves, plastic pens and disposable diapers into the grinder. Also, in went rocks. The grinder handled everything put into it.

The pumps are certified to handle such obstructions like "die-cast plastic cars" and "broken glass," said Randy Bell, a sales executive with Water Resources Technology, who handles sales for the manufacturer.

Bell argued that it would take literally "buckets of sand" to clog them.

The pumps, which are part of what is known as a low pressure system, are also being successfully used in other areas of the Keys, like Grassy Key, Bell said.

Much of the Cudjoe Regional System will use a traditional gravity system, but 2,800 of the 8,800 homes would be serviced by the low pressure system and grinder pumps.

Residents of Cudjoe Gardens, Big Pine Key and Sugarloaf Key would have a combination of low pressure and gravity.

Drabinski did not leave the demonstration totally convinced the pumps were the best way to go.

"Of course when it's new it will do what it needs to do," Drabinski commented after the demonstration was complete.

His concerns are the long-term maintenance and associated costs. He argued the city of Cape Coral debated using grinder pumps with its central sewer system several years ago, but chose not to because they "are not compatible with coastal areas."

Drabinski argued the system the FKAA and county chose is initially cheaper, but in the long run will wind up costing more in maintenance. He proposed reducing the number of grinder pumps by two-thirds, and only placing them "where they make sense."

Zuelch said increasing the number of gravity systems throughout the entire Cudjoe Regional project could add an additional $30 million in up-front costs. FKAA authored its own report to Monroe County officials, challenging Drabinski's findings.

Drabinski argued his proposal would only add an additional $6 million to $8 million to the project, not the extra $30 million.

The FKAA has already chosen two contractors to do the roughly $180 million in work, and the agencies have already hosted a groundbreaking ceremony. The regional system will serve 10,000 homes and businesses from Big Pine Key to Sugarloaf Key.

Drabinski will meet with Aqueduct Authority and county engineering officials on Wednesday to further discuss his concerns with the Cudjoe Regional project.